Equally, if you are going to get your hands dirty with code, and particularly code provided solely through the goodwill of others, you should enter into the spirit of open source and be prepared to learn something yourself. WordPress is designed with novice users in mind, but if you want to mess with the code itself, a small understanding of php – which is not a complicated language – would probably help.

Providing code for free, on your own time, is certainly not an insult, particularly when the recipient is ungrateful and unwilling to spend their own time working a little of it out for themselves.